Lately I've started throwing vibrato into my improving and scale practice just to have a little fun. Im curious as to what the proper technique for this is. I play acoustic only, so obviously its not easy to do. I can get the sound I want, but it takes some effort. Is there a "right" way to do this without straining my hand and arm. I always seem to tighten up when I try to do this.
"How could you possibly be scared of being bad? Once you get past that, it's all beautiful." -Trey Anastasio
You can try it by shaking your hand back and forth first. On an instrument with light strings the change in pressure will produce a change in pitch. You may also be able to harness the shaking motion to wiggle the string back and forth and produce a vibrato that way. You want loose shaking, like shaking water off your hand, not like shaking with rage. :evil:
The above methods won't give you a wide vibrato. A wide vibrato is much more like bending: you turn your wrist to move the string up and down. You don't generally need to go fast. Wide vibratos are usually best when they're a little slower.